Delivery devices are known, for dispensing fluid products, semi-fluids, pastes, gels, creams such as for example colorants, food products or other. Known delivery devices comprise a plurality of containers, or canisters, each suitable to contain a predetermined fluid, colorant or food product, and connected to an associated delivery unit, such as a piston or bellows pump.
The canisters, and the associated delivery units, are mounted on a rotating table suitable to rotate so as to position said delivery units, according to a predetermined sequence, in correspondence with a delivery position. In the delivery position, a specific delivery unit is selectively activated to deliver, in the desired quantity, the fluid of the corresponding containing canister toward an exit container, allowing it to be filled with one or more of said fluids to obtain a fluid with a desired composition and/or formula.
Each canister is also usually provided with mixing means, such as for example a blade, directly or indirectly connected to a movement member that determines the rotation of the table. Alternatively, the mixing means of each canister are coupled with a corresponding actuator, said actuators being commandable independently of each other or in groups. The mixing means are suitable to mix the fluids, also during the movement of the rotating table, so as to keep them in optimum conditions and prevent any unwanted sedimentation or separation thereof.
One disadvantage of known delivery devices—based for example on the piston pump delivery technology—is that they do not have good precision and repeatability of delivery, especially when dispensing small quantities of fluids, corresponding for example to fractions of the quantity delivered for every travel of the plunger or piston.
For example, in the case of micro-volumetric deliveries for the composition of predetermined formulas of colorants, it is necessary to provide a delivery resolution at least equal to a few microliters, which is not always obtainable. Moreover, also due to delivery deviations or offsets, as the number of machine cycles effected increases it is not always possible to precisely deliver the fractions of fluid desired.
Another disadvantage of known delivery devices is that they are rather expensive, as they have to provide a plurality of actuators to mix the color in each canister. This entails a greater probability of mechanical breakdowns and therefore higher production costs and prolonged machine downtimes if a mixer breaks.
One purpose of the present invention is to achieve a device to deliver fluid products which allows to obtain a high delivery precision in every operating condition.
Another purpose of the present invention is to achieve an extremely simple delivery device, both in construction and in assembly, and also in functioning, reducing the motorizations, drives and transmissions to a minimum and hence the possible causes of breakdowns and wear.
Another purpose of the present invention is to achieve a delivery device which allows to reduce its costs, including maintenance costs.
The present invention has been devised, tested and embodied to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.